1. Field of the Invention
The present invention relates to a mount for mounting into a frame a floating bearing for a rotating shaft in order to enable the floating bearing to freely and bidirectionally move longitudinally along the shaft, and more particularly to a mount which restrains the transverse movement of the floating bearing.
2. Description of the Prior Art
In his article, entitled "Right on Target with Winchester," published in Microcomputing in July, 1981, on pages 34-41 Martin Moore discusses the use of hard disks as mass storage devices for microprocessors. According to this article there are two predominant ways to rotate a hard disk at 3600 rpm with little or no side to side or up and down movement. One way is to spin the disk with an AC motor driving the disk spindle, which is the center shaft, by means of a belt and pulley apparatus. The second way is make the spindle of the disk into a DC brushless spindle drive motor. The AC motor is less expensive than the DC spindle drive motor, but the DC spindle drive motor can be held to greater speed tolerances. As the DC spindle drive motor is able to better regulate the rotation speed of the disk it is able to reduce the chance of losing data.
U.S. Pat. No. 4,292,656, entitled Enclosed-Type Magnetic Disc Recording and/or Reproducing Apparatus, issued to Masahiko Fujioka on Sept. 29, 1981, teaches an enclosed magnetic disk recording and/or reproducing apparatus having a disk drive which includes a spindle on which a disk is fixedly coupled and an AC motor the shaft of which is mechanically coupled to the spindle by a belt and a pulley.
U.S. Pat. No. 4,295,162, entitled Reading One-Dimensional Line Image Holograms of a Video Track from a Disc with a Guide Track, issued to W. John Carlsen on Oct. 13, 1981, teaches an optical disk drive which includes an optical disk mounted on a spindle, a pulley fixedly coupled to the spindle and a motor the shaft of which is mechanically coupled to the spindle by a belt and a pulley apparatus.
It is necessary to provide a floating bearing for each of the spindles of U.S. Pat. No. 4,295,162 and U.S. Pat. No. 4,292,656 in order to compensate for thermal expansion or contraction of the frames and other components of the disk drives. The use of the belt and pulley apparatus in each of these disk drives restrains the transverse movement of the floating bearing and maintains the axial position of the spindle with such extreme precision that pre-recorded tracks on the disk are concentric with the axis of the spindle within extremely small tolerances.
U.S. Pat. No. 4,205,357, entitled Disk Drive Unit Incorporating a Field-Replaceable Fixed Disk Assembly, issued to Richard E. Barton, Jack V. Fultz, Yoshiyasu Narahara and Michael S. Shebanow on May 27, 1980, teaches a disk assembly which is normally fixed on disk drive, but which can be removed in the field from the disk drive spindle and replaced on the spindle with extreme precision so that pre-recorded tracks are concentric with the axis of the spindle within extremely small tolerances. The disk assembly includes a mounting ring which fits around the spindle. The ring has three resilient centering flextures which extend slightly radially inwardly of the rest of the ring to engage the spindle and all of which are outwardly deflected substantially the same amount to center the ring on the spindle.
U.S. Pat. No. 4,267,477, entitled Electromotor, issued to Fritz Faulhaber on May 12, 1981, teaches an electromotor which includes a hollow elongated housing, a motor shaft mounted in the housing and a magnet surrounding the motor shaft.
U.S. Pat. No. 4,289,989, entitled Brushless Exciter Rotor Mounting, issued to Patrick J. Schibline on Sept. 15, 1981, teaches a brushless exciter rotor mounting of a sleeveless design.
U.S. Pat. No. 4,243,902, entitled Direct Current motor with Non-Supported Armature Windings, issued to Itsuki Ban, Manshu Shiraki and Kazuhito Egami on Jan. 6, 1981, teaches a direct current motor.
U.S. Pat. No. 4,285,018, entitled Disk File, issued to Richard B. Mulvany and Tulsidass R. Patel on Aug. 18, 1981, teaches a disk file for storing data which includes two major separable assemblies, an HDA assembly and a disk drive assembly. The drive assembly includes a motor which is disposed beneath the horizontal shelf portion of the HDA assembly and which may be coupled to drive the spindle of the HDA assembly.
It is also necessary to provide a floating bearing for a spindle of a disk drive when the spindle is also drive shaft of a DC brushless spindle drive motor in order to compensate for thermal expansion or contraction of the frame and other components of the disk drive. There is no belt and pulley apparatus in the disk drive to restrain the transverse movement of the floating bearing and maintain the axial position of the spindle with any extreme precision that that the pre-recorded tracks on the disk are not concentric with the axis of the spindle within acceptable tolerances. There is presently no method of mounting a floating bearing into a frame of a disk drive which incorporates a DC brushless spindle drive motor so that the floating bearing may freely and bidirectionally travel longitudinally along the axis of the spindle, but it may also maintain the axial position of the spindle with such extreme precision that pre-recorded tracks on the disk are concentric with the axis of the spindle within extremely small tolerances.